Edwardian diamond knot ring. Set with a cushion shape old mine diamond in an open back grain set star shaped setting, with an approximate weight of 0.8 carats. To a central square plaque, further embellished by a fine knot edging which flows to trumpeting split ridged shoulders on either side, to a solid D-shape shank. Marked 18 carat yellow gold, full English hallmarks for Chester, maker's mark 'S.U. LTD', numbered '9341', English, circa 1912.